High sensitivity diode temperature sensor with adjustable current source
US6342997B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 2000 |
| Grant date | Jan 29, 2002 |
| Priority date | — |
| Expiry date | Apr 26, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K3/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A temperature control circuit provides for optical isolation, dry start protection, dedicated load control, manual reset, and relay control in hot water heaters and related applications. The control circuit removes power from a load at a first temperature, and includes a first optical isolation device, a first diode temperature sensor, and a first switching mechanism. The first optical isolation device controls operation of a power source, where the power source is provided to the load, such as a hot water heater heating element. The first diode temperature sensor is biased to provide a switching signal at the first temperature. The first switching mechanism is disposed between the first diode temperature sensor and the first optical isolation device, where the first switching mechanism disengages operation of the first optical isolation device in response to the switching signal. The control circuit can further include a high limit cycling circuit for disengaging operation of the power source at the second temperature. A latching circuit can be used to maintain the temperature control circuit in a switched state until a manual reset occurs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.